/Engine/Source/Runtime/SlateCore/Public/Rendering/DrawElements.h
[FSlateRenderBatch](API\Runtime\SlateCore\Rendering\FSlateRenderBatch) & AddCachedRenderBatch ( [FSlateRenderBatch](API\Runtime\SlateCore\Rendering\FSlateRenderBatch) && NewBatch, int32 & OutIndex )